Art of pipe still distillation



T. E, STOCKDALE Filed March 28, 1928 2 Sheets-Sheet 2 ART 0F PIE STILL DISTILLATION WML/20V@ AMM/Fmg A thereof occurs.

Patented Aug. 30, 1932 UNITED STATES PATENT OFFICE THOMAS E. STOCKDALE, OF WRITING, INDIANA,

PANY, F WRITING, DIDIAN, A.

ABT 0F PIPESTILL DISTILLATIQN appunti nea umn as, 192s.- sem-11.1. 235,505.

The present invention relates to improvements in the art of pipe still distillation of hydrocarbon oils, and will be fully under-4 stood from the following description, illustrated by the accompanying drawings, 1n which: v

Fi re 1 is a side elevation of apparatus suita le for carryingthe invention into effect, shown with av dia ammatic illustration of a pipe still furnace 1n section;

Fig. 2 is an end elevation of the apparatus illustrated in Fig. 1 viewed with the parts on the right of that figure cut. away as indicated by the line 2; and

Fig. 3 is a remixing device of suitable construction for use in accordance with the present invention, shown in section.

The present invention relates more particularly to pipe still distillation processes in` which steam or other vapor is introduced into the system at an intermediate point in the pipe still, and suitably after the oil flowing through the pipe still has been heated to a temperature at which partial vaporization It is illustrated in connection with a pipe still .operation in which, at the point at which the steam is introduced 1nto the pipe still, the stream of oil is subdlvided into a plurality of streams for further flow through the furnace. It will be readily apparent, however, that the invention may be applied to pipe still operations wherein the oil flows entirely through the furnace in a single stream or in which the oil flows through the initial portion of the furnace in a plurality of streams, which may be united into a single stream at the point at which the steam is introduced.

Referring more particularly to the drawings, the numeral 5 indicates diagrammatically in section a pipe still furnace layout, 6 heing a combustion chamber divided by a hridge wall 7 from a convection section 8, through which extend a plurality of series connected 'tubes 9', which are heated by combustion gases from the furnace. It is to be understood that the showing of the pipe still furnace layout is purely diagrammatic and that any suitabley type of pipe still furnace may be employed in accordance with the present invention.

The oilv to be introduced into the system, which may suitably be a crude or reduced crude oil, for example, a. 30 to 35% residuum `from the continuous distillation of Mid-Continent crude, is introduced under suitable pressure through `pi e 10 and flows in series through the tubes 9,being heated therein to a temperature at which some portion of the oil is vaporized. The` oil leaves the series connected pipes 9 through the pipe 1 1 b which the' hot oil and vapors are carried to t e surge tank 12 in which separation of vapors and unvapgrized oil takes place. The surge tank may of any suitable construction, such as, for example, that shown in the copending application of George W. Watts, Serial N o. 264,- 538, filed March 24, 1

From the surge tank, the unvaporized oil passes through 11ne 13 to the hot oil manifold or header 14, which is provided with a plurality of outlets 15, each having a valve 16, the number of these outlets corres onding .to

the number of streams into whlch the oil material is subdivided for further flow through the furnace.

The vapors separated from the oil in the surge tank 12 are conducted by the pipe 17 to the vapor manifold 18, to which steam may be likewise suppliedv through the line 19 controlled by the automatic control valve 20, the operation of which is effected in the mannerhereinafterset forth. The vapor manifold is likewise provided with outlets 2,1, each having a valve 22, the number of these outlets corresponding to the number of outlets 15 from the oil manifold 14.

Each outlet from the hot oil manifold 14 communicates with a remixer 23, with which the corresponding outlet from the vapor manifold 18 likewise communicates. The construction of these remixers'is shown in detail in Fig. 3 and will be more fully herein- -after descri ed. From the remixer, 1n which a substantially uniform intermixture of the separated oil with the separated vapors and steam is effected, the oil flows through lines 24 into parallel-flow series-connected pipes 25 illustrated as in the upper portionofthe pipe still furnace adjacent its roof. The uniform mixture of vapors and oil thus flowsin a lurality of streams through the furnace for urther heating therein, and after leaving the furnace, the streams of oil,are discharged through the lines 26 into the discharge manifold 27, by which the hot oil and vapor mixture is conducted to a flash drum (not shown) or other suitable devices for separation and fractionation of vapors.

A suitable form of construction for the remixing devices 23 is shown in section in Fig. 3. Each remixing device is provided with a casing428, throu lh which the vapor inlet 21, the oil inlet and the outlet 24 leading to the tubes 25 of the pipe still are connected. The vapor inlet 21 is continued withinthe casing as a tubular member` 29 terminating in an orifice plate 30, the' orifice being of a suitable size to secure the desired high velocity of issuing vapors and steam within the mixture. The oil inlet 15 is continued within the casing 28 as a tip ornozzle 31, which terminates slightly below the opening of the vapor orifice tube 29. The oil is thus drawn into the mixer into 'a region of reduced pressure; that is, a pressure lower than that existing in the vapor and steam manifold 18.

In order to equalize the conditions prevailing in lvthe system, and lfor its control as hereinafter shown, the outlet or lower pressure side of each mixer 23 communicates through a line 32 with an equalizing or control manifold 33, with which the oil manifold 14 likewise communicates through the pipe 34, the equalizing manifold 33 being at a substantial elevation above the oil manifold 14. The equalizing or low pressure manifold 33 likewise communicates through the line 35 with the control diaphragm of the automatic steam control valve 20. It is thus apparent that the supply of steam is continuously and automatically controlled t0 maintain uniformly the desired condition of the mixture of oil and vapors reentering the system, and to maintain a substantially constant pressure drop in the remixer, and across the orifice therein. v

It is readily apparent that the supply of steam may be controlled similarly when it is desired to introduce steam at an intermediate point in a pipe still at which the oil has not yet attained a temperature at which vaporization occurs or when, for some reason, the separation of the oil into vaporized and unvaporized portions and remixing at the point of admission of the steam is not desired. In such case, the stream of heated oil leaving the through the pipe 11, instead of passing to the surge tank 12 may be bypassed through the line 36 directly` to the hot oil manifold 14, the valves 37 and 38 in the lines 11 and 13 respectively being closed. At the same time, the valve 39 `in the line 17 may be closed,

p intended to tubes 9 of the pipe stillsteam alone being supplied to the vapor manifold 18. In this Way, a uniform mixture of steam and -oil may be secured'for further flow to the furnace, the proportions of steam and oil being likewise maintained constant.

As has been already stated, the illustration of the pipe still layout as described above is be purely diagrammatic, and for the purposes of illustration, and any desired available layout and flow of oil within the pipe still may be employed. Furthermore, although the invention has been particularly described in connection with a process in which the oil iiows partly through the furnace in a single stream and is then subdivided into a plurality of streams for parallel flow through the remainder of the apparatus, with the preparation of the oil into vapors and unvaporized portions and remixing, or the supply of steam to `the oil and admixture therewith, occurring at the point at which the subdivision into a plurality of streams takes place, it is readily apparent that the invention may be employed in pipe still operations in which the flow throughout the system is in a single stream or in a plurality of streams in parallel. The invention is preferably applied to systems in which the pressure of the outlet of the pipe still is atmospheric or slightly above, but it is readily apparent that it may also be applied to vacuum and pressure distillation systems by a proper control of the pressure differentials.

rlhe process of the present invention is also intended oil containing some'water7 such as pressure still tars or bottoms. In the handling of such oils by the present method, the vaporized portion of the heated material entering the surge tank is substantially entirely steam, the further course followed by such steam being as decribed above in connection with the vapors entering the surge tank. In such an operation the proportions of total steajn to oil is effectively controlled and maintained constant by the present invention. It will be understood in connection with the claims hereinafter that the termvapors as applied to the vaporized portion of the oil stock at the time remixing occurs is to be interpreted as applying broadly to such vaporized portion even when consisting substantially entirely of steam.

I claim:

1. In the art of pipe still distillation of petroleumbils, causing oil to How in a re- `stricted stream through a heatirig zone in a lpipe still furnace, stream of oil at an intermediate point in the stream in the furnace, controlling the supply of said steam by the pressure conditions in the steam-oil mixture in said stream and continuing the flow of the steam-oil mixture in a restricted stream furthery through a. heating zone for further heating thereof.

for the distillation of heavy 2. In the art of pipe still distillation of petroleum oils wherein the oil flows in a restricted stream continuously through a ortion of a pipe still furnace and is subdivided and caused to flow in a plurality of separate streams through the remainder of the pipe still furnace, supplying steam in the se arate streams of oil within thefurnace an controlling the su ply of steam by the pressure conditions in t e steam-oil mixtures in said streams.

3. In the art of pipe still distillation of petroleum oils wherein the oil flows in a restricted stream continuouslyv through a ortion ofa pipe still furnace and is subdivided and caused to flow in a pluralit of streams through the remainder of the pipe still furnace, supplying steam in the divided-streams of oil within the furnace and maintaining substantially identical pressure conditions in the steam-oil mixture in the divided streams in the pipe still and controlling the supply of steam by said pressure conditions.

4. In the art of pipe still distillation of hydrocarbon oils, flowing the oil continuously in a restricted stream through a heating zone wherein the oil is 'brought to a temperature at which vaporization occurs, separatin the heated oil into vapors and unvaporize oil, remixing the vapors and unvaporized oil in a substantially uniform mixture, supplying steam to said mixture, passing the mixture of vapors (including steam) and oilcontinuously through aI heating zone in whlch additional heat is supplied thereto, and controlling the supply of steam to maintain substantially uniform pressure conditions in the vapor-oil mixture.

5. In the art of pipe still distillation of hydrocarbon oils, passing oil 'in a restricted stream through. a heating zone in which it is brought to a temperature at which vaporiza tion occurs, separating vapors and `unvaporized oil, admixing steam with the vapors, subsequently admixing the vapors and steam with the unvaporized oil to form a substantially uniform mixture, passing said mixture continuously in a restricted stream through a hea-tino zone in which additional heat isv imparted thereto, and controlling the supply of steam to the vapors by the pressure conditions prevailing in said mixture.

6. In the art'of pipe still distillation of hydrocarbon oils, passing the loil continuously in a restricted stream through a heating zone wherein it is brought to a'temperature at which vaporization occurs, separating vapors from unvaporized oil, forcing the separated vapors through a restricted opening whereby a region of reduced pressure is formed, admitting the separated unvaporized oil into said region of reduced pressure, to

form therein a uniform mixture of vapor and 'oil, supplying steam in said mixture, and controlling the supply of steam by the pressure conditions prevailing in said mixture. 7; In the art of pipe still distillation of hydrocarbon oils, passing the oil continuously in a restricted stream through a heating Yzone wherein it is brought to a temperature at which vaporization occurs, separating vapors from the unvaporized oil, admixing steam with said vapors to form a. vapor mixture, passing said vapor mixture through a restricted opening, thereby forming a region of reduced pressure, admitting the separated unvaporized oil to said reglon of reduced pressure to form an admixture with the vaporV mixture therein, controlling the supply of steam to the vapor mixture by the pressure conditions prevailing in said mixture region, and passing the resulting mixture of oil and vapors lcontinuously in a restricted stream through a heating zone to impart additional heat thereto. l 8. In apparatus for the pipe Still distillation of hydrocarbon oils, a pipe still, means for conducting oil in av restricted stream through a heating zone therein to bring the oilto a temperature at which va. orization occurs, mea-ns for separatin the eated oil into vapors and unvaporize oil, lmeans for remixing the separated vapors and unvaporized oil, said remixer comprising a casing, a conduit inlet thereinto for va ors, provided With a restricted opening, an a second inlet thereinto for unvaporized oil, said second inlet being provided with a nozzle terminating adjacent the outlet side of said restricted opening, and means for conducting the mixture formed by said remixer in a restricted stream through a heating zone in said pipe still for the supply of additional heat thereto.

9. In apparatusfor the pipe still distillation of hydrocarbon oils, a pipestill, means for conducting oil in a restricted stream through a. heating zone therein to bring the oil to temperature at which vaporization oc- 110 curs, means for'separating the heated oil into vapors and unvaporized oil, means for dividing the separated vapors and unvaporized oil into a plurality ofV corresponding portions, a remixer for uniformly'mixing each 115 of the correspondin portions of vapors and unvaporized oil to orm a plurality of unform'oil-vapor mixtures, each of said remixers comprising'a casing, a vapor inlet conduit thereinto having al restricted opening, l2- an oil inlet thereinto having a nozzle terminating adjacent the outlet side of said restricted opening, whereby oil-vapor mixtures are formed in each of said remixers, means yfor equalizing the pressure conditions in all 125 said remixers, and means for conducting each of the resulting oil vapor mixtures in separate streams to a heating zone of said pipe still. for the.. supply of additional heat thereto./ v

vheating zone of said 10. In apparatus for the pipe still distillation of hydrocarbon oils, a pipe still, means for conducting oil in a restricted stream through a heating zone therein to bring the oil to temperature at which vaporization occurs, means for separating the heated oil into vapors and unvaporized oil, means for dividing the separated vapors and unvaporized oil into a plurality of corresponding portions, a remixer for uniformly mixing each of the corresponding portions of vapors and unvaporized` oil to form a plurality of uniform oil-vapor mixtures, each of said remixers comprising a casing, a vapor inlet c onduit thereinto `having a restricted opening, an oil inlet thereinto having a nozzle terminating adjacent the outlet side of said restricted opening, whereby oil-vapor mixtures are formed in each of said remixers, and means for conducting each of the resulting oil-vapor mixtures in separate streams to a pipe still for the supply of additional heatgthereto.

11. In apparatus for the pipe still distillation of hydrocarbon oils, a p1pe still, means for conducting oil in a restricted stream through a heating zone in said pipe still to bring said oilto a temperature at which vaporization occurs, means for separating the heated oil into vapors and unvaporized oil, means for suhdividingthe separated vapors and unvaporized oil into a plurality of corresponding portions, a plurality of remixers, means for supplying corres onding portions of the separated vapors an unvaporized oil to each said remixer, means for supplying steam to each remixer, and means for Vconducting each of the resulting mixtures from said remixers in separate restricted streams through a heating zone in said pipe still to impart additional heat thereto.

12. In apparatus for the pipe still distillation of hydrocarbon oils, means for conducting oil in aI restricted stream through a heating zone in said pipe still to be brought to a temperature at which vaporization occurs, means for separating theA heated oil into vapors and unvaporized oil, means for supplying steam to the separated vapors to form a steam-vapor mixture, means for subdividing the steam-vapor mixture and the unvaporized oil into a lurality of corresponding portions, a plurahty of remixers, means for supplying corresponding portions of the steam vapor mixture and unvaporized oil to each remixer to form an oil-vapor mixture therein, means for controlling the supply of steam to the vapor mixture by the pressure conditions prevailing in said oil-vapor mixtures, and means for conducting each of said oil-vapor mixtures in a plurality of separate streams throu h a heating zone in pipe still to impart addltional heat thereto.

13. In the art of pipe still distillation of hydrocarbon oils, passing oil in a restricted portion of the vapors stream through a heating zone in which it is brought to a temperature at which vaporization occurs, separating vapors and unvaporized oil, admixing steam with the vapors, subdividing the steam-vapor mixture and the unvaporized oil into corresponding portions, subsequently admixing corresponding portions of said vapor mixture and unvaporized oil to form a plurality of substantially uni-- form mixtures, passing each' of said mixtures continuouslyin 'a separate restricted stream through a heating zone inwhich additional heat is imparted thereto, and controlling the supply of steam to the vapors by the pressure conditions prevailing in said mixtures of vapors and oil.

14. In the art of pipe still distillation of hydrocarbon oils, passing oil in a restricted stream through a heating zone in which it is brought to a temperature at which vaporization occurs, separating vapors and unvaporized oil, admixing steam with the vapors, subdividing the resulting vapor mixture and the' unvaporized oil into corresponding portions, subsequently admixing corresponding portions of the vapor mixture and unvaporized oil to form a plurality of substantially uniform mixtures, equalizing the pressure vconditions in said mixtures, passing each of said mixtures continuously i'n separate restricted streams to a heating zone in which additional heat is imparted thereto, and controlling the supply of steam to the vapors by the equalized pressure conditions prevailing in said mixtures.

15. In the art of pipe still distillation of hydrocarbon oils, passing the oil continu-y ously in a restricted stream through a heating zone wherein it is brought to a temperature Iat Which vaporization occurs, separating vapors and unvaporized oil, subdividing the separated vapors and unvaporized oil into corresponding portions, forcing each through a restricted opening wherebyy a region of reduced pressure is formed, admitting the corresponding portion of the separated unvaporized oil into said region of reduced pressure, thereby forming in each of said regions of reduced pressure a uniform mixture of vapor and oil, supplying steam in each of said mixtures, controlling the supply of steam by the pressure conditions. prevailing in the resulting mixtures, and forcing each ot' the resulting mixtures in separate x restricted streams through a heating zone in which additional heat is imparted thereto. l

16. In the art of pipe still distillation of hydrocarbon oils, passing the oil continuously in a restricted stream through a heating zone wherein it is brought to a temperature at which vaporization occurs, separating the vapors and unvaporized oil, subdividing the separated vapors and unvaporized oil into corresponding portions, forcing each l Htl) portion of the vapors through a restricted opening whereby a region of reduced preshydrocarbon oils, passing the oil continu-` ously in a restricted stream through a heating zone wherein it is brought to a temperature atwhich vaporization occurs, separating the vapors and unvaporized oil, admixing steam with said vapors to form a vapor mixture, subdividing the resulting vapor mixture and the unvaporized oil into correhill filth till? sponding portions, passing each portion of said vapor mixture through a restricted opening, thereby forming a region of reduced pressure, admitting each of the separated unvaporized oil portions into each of said regions of reduced pressure to form an' admixture with the vapor mixture therein, equalizing the pressure conditions in said reduced pressureregions, controlling the supply-of steam-to the vapor mixtures by the pressure prevailing in the mixtureof oil, vapor and steam, and passing each of the resulting| mixtures of oil and vapors continuously in separate restricted streams through a heating zone to impart -additional heat thereto.

i8. I t f th t'll d n appara us or e plpe s 1 '1s iii said conduit beyond the point of supply.

tillation of hydrocarbon oils, a pipe still, serially connected pipes therein, means for supplying oil to flow through said pipes to he heated to a temperature at which vaporination occurs, a drum, means for discharging the heated oil into said drum for separation of vapors and un aporized oil, a

' remixer, means for supplyiric` the separated vapors and unvaporized oil from said drum to said remixer, means for sup lying steam to the remixer, additional seria 1y connected pipes in said ipe still, means for forcing 'the mixture o and steam formed at said remixer through said pipes to impart additional heat thereto, and means for controlling 'the supply of steam to the remixer by the pressure conditions prevailing in said mixturel of oil, vapors and steam.

19. In apparatus for pipe still distillation of hydrocarbon oils, a pipe still furnace, a pluralit of serially connected pipes therein, means or forcing oil through said pipes to he heated to a temperature therein at which vaporization occurs, a chamber, means for vapors and unvaporized oil discharging the heated oil into said chamber for separation of Avapors and unvaporized oil, means for mixing the separated vapors'with steam to form a vapor mixture,

a remixer having a restricted vapor inlet,

means for supplying the vapor mixture tol said 'remixer throu h said'restricted vapor inlet, whereby a re uced pressure region is formed in said remixer, means-for supplying the separated unvaporized oil to said remixer in said reduced pressure region, means for controlling the supply of steam to the vapor mixture by the pressure conditions prevailingin the mixture of oil, vapor, and steam, and means for passing the mixture of oil, vapor and steam through said pipe still furnace for the supply of additional heat thereto.

20. In the art of pipe still distillation of hydrocarbon oils, passing a water-containing heavy. oil in a restricted stream through a heating zone wherein it is brought tov a temperature at which vaporization of water occurs, separating the steam and unvaporized oil, supplyingadditional steam to the separated steam, admixing the'total steam with the separated oil, controlling the 'supply of steam to maintain the proportion of total-steam in the'mixture substantially con-` stant, and passing the steam-oil mixture,in a restricted stream through a-heating zone to impart additional `heat thereto.

21. lIn apparatus for the pipe still distillation of h drocarb0n oils, a furnace, series-connected" p'ipes forming a conduit in said furnace, means for forcing oil through the said conduit, means for supplying steam to the stream of oil at an intermediate point in the conduit, and means responsive to the ressure conditions of the steam oil mixture of said steam forcontrolling the supply of steam.

22. In apparatus for the pipe still distillation ofhydrocarbon oils, means for conducting oil in a restricted stream through a heating zone to bring the oil to a temperature at which vaporization occurs, means for separating the heatedvoil `into vapors and unvaporized oil, means for remixmg the separatedva'pors and unvaporized o1l, means for supplying steam to said remixlng means, means responsive to the pressure of the remixed'va4 ors and unvaporized oil for controlling t e supply of steam, and means for conducting the remixed vapors and unvaporized oil in a restricted stream and through a second heating zone for the supply of additional heat thereto. Y

In testimony whereof I have hereunto set my hand this day of February, 1928.

THOMAS E. STOGKDALE.

CERTIFICATE or CORRECTION.

Patent No. 1,874,212. August 3o, 1932.

THOMAS E. STOCKDALE.

It is hereby certified thaterror appears in the printed specification of the above numbered patent requiring correction as follows: Page v1, line 69, after "1928" insert the comma and words which has matured into patent NO. 1,831,051;

page 3, lines 82 and 83, claim 7, strike out the words "said mixture region" and insert instead the resulting mixture of Oil and vapors; page 5, iines 34 and 35, claim 17, strike out the words" prevailing in the 4mixture of oil, vapor and steam" and insert instead conditions prevailing in the resulting mixtures;

and that the said Letters Patent should be read with these corrections' therein that the same may conform to the record o f the case in the Patent Office.

Signed and sealed this 22nd day of November, A. D. 1932.

A M. 3. MOOre, (Seal) Acting Commissionervof Patents. 

